Have your children disassembled a flashlight to see what's inside? They know then that it requires batteries to work. Guess what? They can build a flashlight that does not require batteries - an electromagnetically charged flashlight, also known as a "shake flashlight" or a "Faraday flashlight".

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Materials Needed

Smarty has built her shaker flashlight in a class organized by our local organization for gifted children, Lyceum. This particular design combined flashlight function with a fun "colored light display", and kids actually soldered a circuit to make it work. Instructables build is similar, but does not require soldering. You will still need some electronic circuitry components to make it work:

How Is It Made?

In our class, kids first listened to instructions where the teacher explained to them how to put together a circuit, how to tell apart the end points of LEDs (long leg is plus, short leg is minus), and, most importantly, safety rules and mechanics of soldering. Even though Smarty never held a soldering iron in her hands before, she plunged into this project with great enthusiasm following printed instructions and occasionally asking an instructor for help. The class took about an hour longer than originally planned, but, in the end, all kids had a working shaker light:

How Does It Work?

Again, we were lucky, because our instructor gave an excellent introduction to the history of electricity and magnetism starting with Luigi Galvani, continuing to Michael Faraday, and then wrapping up with the battle between Edison and Westinghouse-Tesla. This shake light (also known as a Faraday flashlight) uses the Faraday law - voltage is produced when the magnet inside of the tube moves quickly back and forth within copper coiled wire. You can see a fun intro to the Faraday law in this video:

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You are welcome to use any ideas from my blog for your own personal use. You may not use my pictures without permission. If you blog about something that you have learned here, I will appreciate linking back to my blog. May the Force be with you!